In general, a fluid pressure cylinder includes a cushion mechanism for decelerating a piston rod by generating a cushion pressure in the vicinity of a stroke end of a piston rod (JP6-40326Y2).
In a fluid pressure cylinder disclosed in JP6-40326Y2, the piston rod has a normal diameter portion and a small diameter portion formed having a diameter smaller than that of the normal diameter portion. The piston is connected to the piston rod so as to face a stepped portion between the normal diameter portion and the small diameter portions. On an outer periphery of the small diameter portion of the piston rod, a cylindrical cushion bearing is movably provided between the stepped portion and the piston rod. An inner diameter of the cushion bearing is larger than an outer diameter of the small diameter portion, and a gap (inner peripheral gap) is formed between the cushion bearing and the small diameter portion.
Moreover, in the fluid pressure cylinder disclosed in JP6-40326Y2, a cylinder head has a bore formed capable of entry of the cushion bearing. In an expanding operation of the fluid pressure cylinder, the cushion bearing enters the bore of the cylinder head in front of a most expanded position. At this time, the cushion bearing is pressed onto a step of the piston rod by a pressure inside a rod side chamber, and flowing of an operating fluid from the rod side chamber to a port is limited only through a gap (outer peripheral gap) between the cushion bearing and the bore. Resistance is applied to a flow of the operating fluid moving from the rod side chamber to the port through the outer peripheral gap, and the piston is decelerated.